Abstract: A method for processing data packets in a communication network includes establishing a path for a flow of the data packets through the communication network. At a node along the path having a plurality of aggregated ports, a port is selected from among the plurality to serve as part of the path. A label is chosen responsively to the selected port. The label is attached to the data packets in the flow at a point on the path upstream from the node. Upon receiving the data packets at the node, the data packets are switched through the selected port responsively to the label.

Abstract: A method for communication includes operating a network element, which includes multiple ports and multiple interconnected processing units, such that each processing unit is assigned to process packets that are communicated over a respective set of one or more of the ports. Each processing unit stores a respective list, which indicates one or more multicast packet streams that are permitted for forwarding by the network element, and further indicates a respective subset of the ports over which each of the multicast packet streams is permitted for forwarding. A request relating is disturbed among the multiple processing units, and the respective list in each processing unit is updated responsively to the request. Multicast packets associated with the given multicast packet stream are forwarded selectively by the processing units in accordance with the respective updated lists.

Abstract: A method for communication includes configuring a plurality of ring nodes to communicate over a communication network that includes two or more overlapping communication rings, each ring including two unidirectional ringlets in mutually-opposite directions. A data packet including one or more header fields is accepted at an ingress ring node. An egress ring node to which the data packet is to be forwarded by the ingress ring node is determined. A subset of the rings including one or more common rings that are connected to both the ingress and egress ring nodes is identified. A ringlet of a ring among the one or more common rings is selected responsively to a respective value of at least one of the header fields of the packet. The data packet is forwarded from the ingress ring node to the egress ring node over the selected ringlet.

Abstract: A method for communication over a bi-directional ring network includes provisioning a virtual private local area network service (VPLS) over the bi-directional ring network. The VPLS includes connection termination points provisioned respectively on a plurality of the nodes so as to connect each of the plurality of the nodes to a second network external to the ring network. As long as the nodes and spans are fully operational, one or more of the connection termination points are maintained in a deactivated state, so that no more than one of the connection termination points to the second network is active. The nodes exchange messages indicative of a failure associated with the bi-directional ring network, causing at least one of the deactivated connection termination points to be activated so as to maintain connectivity among the users of the VPLS without creating a loop in the VPLS via the second network.

Abstract: A method for communication via a ring network that includes a plurality of nodes. The method includes receiving at a first node in the ring network a data packet transmitted over a virtual private LAN service (VPLS), the data packet including an identification of the VPLS. The first node reads the identification from the data packet. Responsively to reading the identification, the first node forwards the data packet to at least one second node in the ring network that is associated with the VPLS.

Abstract: A method for processing data packets in a communication network includes establishing a path for a flow of the data packets through the communication network. At a node along the path having a plurality of aggregated ports, a port is selected from among the plurality to serve as part of the path. A label is chosen responsively to the selected port. The label is attached to the data packets in the flow at a point on the path upstream from the node. Upon receiving the data packets at the node, the data packets are switched through the selected port responsively to the label.

Abstract: A method for data communications includes receiving a time-division-multiplexed (TDM) input signal carrying a payload comprising data and determining whether the data comprise synchronous or non-synchronous data. A first encapsulation scheme is selected if the data comprise synchronous data, and a second encapsulation scheme is selected if the data comprise non-synchronous data. The data are encapsulated for transmission over a packet-switched network in accordance with the selected encapsulation scheme.

Abstract: A functionality and method for determining aggregate data transit bandwidth requirements for the nodes of an Ethernet ring network for traffic management and to improve the operation, efficiency, and Quality of Service. An aggregate bandwidth database is produced, based on a priori knowledge of the ring network, including topology, path utilization, bandwidth sharing, and failure protection scenarios. Aggregate bandwidth requirements are determined independent of the actual real-time data traffic rates, and without requiring any actual real-time data traffic rate information. Aggregate bandwidth is automatically determined upon configuration or reconfiguration of the ring network.

Abstract: A method for communication includes, in a communication network that includes multiple ring nodes arranged in at least first and second ring networks that are connected by two or more of the ring nodes serving as interconnect nodes, accepting at the two or more interconnect nodes respective copies of a data packet, which is sent from a source user node connected to the first ring network. An attribute is extracted from the respective copies of the data packet at each of the interconnect nodes, and a predefined mapping function is applied to the extracted attribute so as to select a single interconnect node for forwarding the data packet to the second ring network. A single copy of the data packet is forwarded to the second ring network only from the selected interconnect node, while refraining from forwarding other copies from the other interconnect nodes.

Abstract: A method for communication includes configuring a plurality of ring nodes to communicate over a communication network that includes two or more overlapping communication rings, each ring including two unidirectional ringlets in mutually-opposite directions. A data packet including one or more header fields is accepted at an ingress ring node. An egress ring node to which the data packet is to be forwarded by the ingress ring node is determined. A subset of the rings including one or more common rings that are connected to both the ingress and egress ring nodes is identified. A ringlet of a ring among the one or more common rings is selected responsively to a respective value of at least one of the header fields of the packet. The data packet is forwarded from the ingress ring node to the egress ring node over the selected ringlet.

Abstract: A method for budgeted learning of link information in a network includes providing a database to contain the link information, for use by an entity connected to the network in transferring traffic over the network, and setting a maximum rate for addition of entries to the database. New entries to be added to the database are determined responsive to the traffic on the network during a learning period. The new entries are added to the database only if the addition of the entries during the learning period has not exceeded the maximum rate.

Abstract: A maintenance entity for an Ethernet Connectivity Fault Management (CFM) domain. The maintenance entity comprises a port definer module and a connection which is connected to a group of aggregated link. The port definer module examines a designated link of the group by forwarding CFM messages via the designated link.

Abstract: A method for communication includes encapsulating multiple data packets, which carry data and have respective drop precedence (DP) values selected from a range of possible DP values, to produce a concatenated frame of a transport protocol. A composite drop precedence (CDP) value is assigned from the range to the concatenated frame using a pseudo-random assignment function that depends on a distribution of the DP values of the data packets in the concatenated frame. The concatenated frame is transported through a communication network using the transport protocol, in accordance with the pseudo-randomly assigned CDP value.

Abstract: A network node in a communication network includes a plurality of ports, at least a subset of which is grouped in a link aggregation (LAG) group. The node includes packet processing logic, which is coupled to receive data packets having respective destination addresses that specify forwarding the packets to groups of multiple recipients through at least one of the ports and to process the data packets so as to forward only a single copy of each of the data packets via the output ports in the subset, while distributing forwarded copies of the data packets among the output ports in the subset so as to balance a traffic load within the LAG group.

Abstract: A method for communication is used in a communication network that includes multiple ring nodes arranged in at least first and second ring networks, which are connected by one or more of the ring nodes serving as interconnect nodes. A data packet is accepted from a source user node served by the first ring network, for forwarding to a destination user node served by the second ring network. An identifier, which identifies an interconnect node in the first ring network through which the data packet is to be forwarded to the second ring network, is attached to the data packet in the first ring network. The data packet is forwarded over the first ring network, accepted at the interconnect node and, responsively to the identifier, forwarded from the interconnect node to the second ring network. The data packet is forwarded over the second ring network to the destination user node.

Abstract: A method for communication includes coupling a group of switches in a Layer-2 bridged network. The interfaces of the switches are configured so that at least one interface of at least one of the switches is configured as a first interface type, and a plurality of other interfaces are configured as a second interface type. Upon receiving frames through the interfaces of the first and second types for transmission over the network, the received frames are labeled with corresponding first and second type indications. The frames are forwarded through the Layer-2 bridged network using the switches responsively to the type indications. Frames labeled with the second type indication are permitted to be transmitted through the interfaces of the first type and prevented from being transmitted through the interfaces of the second type.

Abstract: A network element includes a backplane, which includes a backplane memory holding first medium access control (MAC) address values. The network element further includes multiple tributary modules coupled to the backplane, which include network interfaces that are configured to communicate over network trunks using MAC addresses that are respectively assigned to the network interfaces. The network element further includes a common function module (CFM), which communicates with the tributary modules and the backplane memory via the backplane, and which includes a CFM memory holding second MAC address values. The CFM is arranged to assign the MAC addresses to the network interfaces by selecting the MAC addresses from among the first MAC address values when the CFM is able to access the backplane memory, and by selecting the MAC addresses from among the second MAC address values when the CFM is unable to access the backplane memory.

Abstract: A method for communication between first and second nodes via a communication network includes assigning multiple communication ports in two or more network nodes between the first and second nodes to serve as member ports of a multi-homing group (MHG). Each of the member ports is associated with a different, respective communication path between the first and second nodes via the communication network. A frame transmitted from the first node to the second node is accepted at the two or more network nodes. The frame has a header including header fields. A single port is selected from among the member ports by applying a hashing function to one or more of the header fields at each of the two or more network nodes. The frame is forwarded via the selected port over the respective communication path that is associated with the selected port.

Abstract: A method for establishing a connection through a communication network that includes multiple segments includes providing a sharing definition defining a sharing of bandwidth among connections in the network. Two or more candidate routes for a new connection to be established through the network are identified. For each of the two or more candidate routes, a cumulative additional bandwidth reservation to be allocated to the new connection in the segments along the candidate route is calculated responsively to the sharing definition. A preferred route having a minimum value of the cumulative additional bandwidth reservation is selected out of the two or more candidate routes. The new connection is established using the preferred route.

Abstract: A method for communication includes configuring a network node having at least first and second line cards, the line cards having respective ports, to operate as a distributed media access control (MAC) bridge in a Layer 2 network. Each of the line cards has a respective forwarding database (FDB). Upon receiving a data packet on a port of the network node from a MAC source address, the data packet is conveyed to at least the first line card for transmission to the MAC destination address. The MAC source address of the data packet is checked against the records in the FDB of the first line card. If the FDB does not contain a record of an association of the MAC source address with the port on which the data packet was received, the record is added to the FDB of the first line card, which sends a message to at least the second line card informing the second line card of the association.